1. Field of the Invention
The present invention relates to an information processing apparatus for editing page description language (PDL) data expressed in a hierarchical structure, an information processing apparatus control method, and a storage medium.
2. Description of the Related Art
<POD, Variable Printing and PDF/VT>
With the spread of printing systems aimed at the print-on-demand (POD) market, variable printing, in which a printed product customized for each customer is printed, has been gaining attention. Variable printing has the advantage that a printed product suited to the customer can be produced, because printing can be performed by reading a database and changing the contents of each and every page for each customer.
Against this background, the standardization process of ISO 16612-2 portable document format/variable data and transactional (PDF/VT) has been progressing as a language specification for variable printing. A characteristic of PDF/VT is that it can be used even for existing PDF work flows by adding a specification for variable printing or transaction printing with PDF as a base.
<PDF/VT Characteristics (Hierarchical Structure: DPart and Metadata: DPM)>
PDF/VT can build a PDF page by adding hierarchical structure layers called document parts (DParts). Further, arbitrary metadata called document part metadata (DPM) may be added to each DPart. A wide variety of information, such as “postcode”, “address”, and “name”, can be added to the metadata expressed in a hierarchical structure (layered metadata) based on a relationship between a key and a value.
Further, PDF/VT has a root node relating to the hierarchical structure, called a document part root (“DPartRoot”). In addition, the metadata in the DPartRoot is stored as layered metadata based on a relationship between a key and a value concerning record information obtained when the database is read. This hierarchical information is managed by a “record level” key.
Further, the PDF/VT layered metadata can be freely edited by adding or deleting DParts to/from the hierarchical structure. Consequently, the layers can be used for the purpose of grouping by adding metadata to the layers so that the layers have a meaning.
<How PDF/VT is Used to Realize Variable Printing>
A job definition format (JDF) is used along with PDL data, such as PDF/VT, to control the whole printing workflow. When performing variable printing using JDF and PDF/VT, customer information is acquired by referring to the PDF/VT metadata, and customized for each customer for printing. Further, an engine for reading the JDF and performing imposition processing, performs imposition processing while repeatedly referring to the record level layers of the PDF/VT.
By using PDF/VT together with printing control information such as JDF, PDF/VT enables printing control in which only a page matching a specific postcode is printed based on layered metadata. More specifically, PDF/VT enables control in which only a specific group, namely, a specific postcode, is printed using printing control information such as JDF.
Thus, since PDF/VT includes layered metadata, which can be grouped by freely editing the layers, PDF/VT can realize detailed printing control.
Japanese Patent Application Laid-Open No. 11-205736 discusses a method for graphically editing a hierarchical structure and metadata accompanying the hierarchical structure.
Even when a PDF/VT hierarchical structure is changed by editing the PDF/VT to perform grouping, obviously the “record level” key needs to be correctly managed. Further, to perform printing control, not only is it necessary to correctly manage the “record level” of the PDF/VT itself, but the references in the JDF also need to be correctly stored. Consequently, there is a need for metadata editing that is realized in a hierarchical structure by a simple method, without destroying the reference relationship.
However, Japanese Patent Application Laid-Open No. 11-205736 does not consider points such as grouping by using the layered metadata, or storing the number of layers required for printing control for the hierarchical information that can be changed by grouping. Consequently, there is a problem that the record level may be set to a layer not intended by the user due to metadata editing.